Improvement in valves for steam-engines



u IMI Stabat gaat anta..

JOSEPH W. HOPKINS, OF BROOKLYN,- E. D., NEW YORK, ASSIGNOR TO IIIMSELF AND WILLIAM H. M. PYE,` OF SAME PLACE.

LettersPatentliTo. 94,750, dated September 14, 1869.

IMPROVEMENT IN VALVES FOR STEAM-ENGINES.

The Schedule referred to in these Letters Patent and making part of the same.

To all-whoml it mag/.concern Figure 2 is the plan of the same, with the cover of the steam-valve removed; and V Figurey 3 is a cross-section, at the line x x of lig. 2. Similar marks of reference denote the same-parts. This invention relates to a means for giving motion to the main valve of the engine, by the action of a small secondary valve that is .worked by tappets and direct action from the piston-rod.

In valves that are operatedvby a secondary valve, difficulty frequently arises in constructing the parts so as to be easily accessible for examination, cleansing, or repairs, because the said parts have generally been enclosed within the steam-chest.

My invention is made with a view to obviating these inconveniences, andconsists in a secondaryvalve within the steamchest,ope1ated by a rock-shaft and moving a piston in a secondary cylinder, in combination with the primary valve and 'rock-shaft, that are actuated by the pistou ofthe secondary cylinder.

In the drawinga, is the cylinder;

b, the piston;

c, thelpiston-rod;

d, the steam-chest;

c and j, the ports;` and g, the exhaust.

h is the steam-valve, and

k, the rock-shaft, for actuating the same.

These parts are of any usual construction or desired size, and operate in the ordinary manner in admitting steam and exhausting.

Within the steam-chest v(l is the secondary valve t', that is operated by a rock-shaft, l, and toe, upon which rock-shaft Z are adjustable arms, on, against which the Iopposite sides ofthe inclines u act alternately, to give said rock-shaft a partial rotation at the ends of the stroke.

The valve t' is made with side-bearing ribs, in order that it may stand more rmly upon its seat, but the valve-portion proper is at one end, as seen in iig. 3.

In the seat of this valve are three po1ts,.1, 2, and 3, the first connecting with the bottom of the secondary cylinder @that is placed in a convenient position at the sideof the main steam-cylinder a., or valve chest.

The port 2 connects with the upper part of the cylinder p, and the port 3 leads to the n'iain exhaust g.

The piston o has a rod, q, that is connected with the arm o' of the main rock-shaft la.

` It will now be understood that the secondary valve,

being small, is operated with but little power, and snpplies the steam to the cylinder p,and' thereby moves the valve h, through the medium of the piston o, rod

q, arm r, and rock-shaft; and the parts can be adjusted witlr the greatest accuracy, so as tor'admit steam to the secondary cylinder at exactly the proper moment,

.according to the position of the piston of the-main engine, the arms m being movable for that purpose.

That I claim, and desire to secure byA Letters Patent, is`

The secondary valve i, actuated by the rock-shaft l, in combination with the cylinder p, piston'o, lod q, and arm r, for operating the valve of the main engine in the manner specified.

In witness whereof, I have hereunto set my signature, this 20th day of July, 1869.

Witnesses: JOSEPH' W. HOPKINS.

GEO. vI). WALKER, Gno. T. PINCKNEY. 

